Feed control device for flat grinding machines



June 14, 1960 H. MADRICH FEED CONTROL DEVICE FOR FLAT GRINDING MACHINESFiled Feb. 5, 1957 United States Patent() FEED CONTROL DEVICE FOR FLATGRINDING MACHINES Hermann Miidrich, Frankfurt am Main Fechenheini,Germany, assignor to Diskus-Werke, Frankfurt am Main, Akt.-Ges.,Frankfurt am Main Fechenheim, Germany Filed Feb. 5, 1957, Ser. No.638,361 7 Claims priority, application Germany Mar. 10, 1956 8 Claims.(Cl. 51-131) This invention pertains to fiat grinding machines, and moreparticularly to a feed control device capable of limiting the feedmovement of the grinding tool and including a preferably adjustablegauging'means which c'ooperates with a feed disconnect member and can beinstalled at a suitable distance from the place where the work-piece ispositioned.

The invention is characterized by the features that a gauging meansincluding a feeler member having a contact portion of abrasion-resistantmaterial is directly acted upon by the grinding tool; that this feelermember forms with the disconnect member a single operating unit, thefeeler member being movably or displaceably arranged and subjected toadjustable spring action; that the gauging means is mounted on a supportatv suitable distance from the area Where the grinding is done; and thatthe contact between the grinding tool and the feeler member only takesplace immediately before the desiredfinal dimension of the work-piece isproduced (that is to say, within a distance of 0.002 to 0.005 mm.between the tool surface and the final surface of the piece), so thatduring an entire working operation the grinding tool is just once incontact with the gauging means for disconnecting the feed means via thedisconnect member.

By means of an arrangement of the aforedescribed kind the inventionachieves the result that the length of the displacement of the feelermember and of the moving part of the disconnect member as well as thenumber of disconnections of the feed means of the grinding tool arereduced to an absolute minimum, which in connection with the use on thefeeler member of a portion of abrasion-resisting material guaranteeshighest precision and longest lifetime of the feed control deviceaccording to the invention.

In machines where the grinding surface of the grinding tool extends in avertical plane the feeler member may be directly coupled to thedisconnect member, so that upo'n displacement of said feeler memberunder the action of the grinding tool contacts are opened in thedisconnect member for the disconnection of the electrically operatedfeed means.

On the other hand, in forms of machines where the grinding surface ofthe grinding tool extends in a horizontal plane, the feeler member maybe a pivotally supported lever which operates the disconnect member viaa transfer member.

Additional features and advantages of the invention will be understoodfrom the following detailed description taken in connection with theaccompanying drawings forming a part of this specification and in whichtwo embodiments of the invention have been shown by way of example.However, I wish to say that the invention is not confined to any strictconformity with the showing of the drawings but may be changed ormodified, so long as such changes or modifications mark no materialdeparture from the salient features of the invention as expressed in theappending claims.

2,94%,224 Patented June 14, 1960 In the drawings, in which like partsare referred to by the same reference numerals,

Fig. 1 is a lateral view, partly in section, of a feed control deviceaccording to the invention, showing a grinding toolextendingin avertical plane;

Fig. 2 is a'lateral view of a modified form of machine showing agrinding tool extending in a horizontal plane in the same manner as thesurface of the work-piece to be treated; and the feed control device isarranged parallel with the axis of the grinding tool;

Fig. 3 is a lateral view, partly in section, and on an ice enlargedscale, of the feed control device of Fig. 1.

In the embodiment illustrated in Fig. l the reference numeral 1designates the grinding tool adapted to be fed device and consists ofrelatively abrasion-resistant material. The feeler 7 is provided with anaxially extending groove 8 which is engaged by a stop screw or lockingscrew 9 securing in this way the entire device in its adjusted positioncorresponding to the final-working position of the tool 1 in which thegrinding operation is desired to be stopped.

In the form of construction shown in Fig. 2 the workpieces 10 arearranged on a circular supporting table 11 with the grinding tool 1being adapted to be fed in the directions indicated by the arrows 11.Also in this form of construction the feed control device isvstation'arily arranged (similarly as in the construction showniinFig. 1) by means of a bearing block 6 and adjustably supported by meansof the bar 17 lockable in the guiding means 4, whereby the rod 17 isshiftably adjustable in the directions indicated by the arrows III. p

At the lower end of the shaft 17a feeler in form of a two-armed lever 13is arranged for rotation about a pivot 12, the lever 13 carrying on itsend 14 the checking portion 6 which cooperates with the grinding tool 1,while the opposite end 15 of the lever 13 cooperates with the tip 16 ofthe shiftable transfer rod 7' operating like the feeler 7.

Fig. 3 shows the specific construction of the feed-control device ofFig. 1. The checking portion 6 of the feeler member is a block mountedin a'sliding support 18 positioned at the end of a supporting bar 19 ofsmaller cross-section than the support 18 and which at its'bpposite endterminates in a U-shaped end portion 29. The two legs 21 and 22 of the-U-shaped portion 20 are provided with bores 23, 2.4 through whichextends a shaft 31 carrying a stationary contact member 25, while theends of the legs 21, 22 abut against the supporting means 27 of theshiftable contact member 26. The U- shaped end 20 and the contactsupport 27 are positioned and guided within the cylindrical casing 28.The contact-support 27 is acted upon by a pressure spring 29 in thedirection toward the stationary contact 25 the pretension of spring 29of the shiftable contact 26 being adjusta'ble by means not shown. On theother hand, the position of rest of the checking block 6 ,is adjustablein axial direction to the desired degree by means of amicrorneter screw30 mounted on the stationary block 3' and guide 4 and engaging anoutside thread on the hollow shank 2' attached to body 2 and slidable inthe guide means 4. Connected to the shaft 31 carrying the-stationarycontact 25 is a cable 32 leading to the switch box (not illustrated inthe drawings) controlling the means for the feeding of the grinding tooland by means of which cable the switching operation consistingin the"2,9403 V -7 V -t separation of the contacts 25 and 26 when the feelermember is shifted, is passed on to the switch box.

A feed control device as illustrated in Figs. 1 to 3 'opera'ies if p f l7 1'7 :T J The grinding tool 1 is adapted to machine a-work-piecemounted on a circular supporting table ll on other support means incooperation withya feeding device of known construction. iiAs'soonasduring the feeding action the ;.grinding:tool advances into closepronimityoffthe required final dimension of the piece, that isto say,within between 0.002 and 0.005 mm. fromv the final dimension thechecking block 6jis touchedby the-grinding .tool, so

that when the forward feeding of the grinding tool continues, thechecking block. isforced backwardagainst the action of spring29- and thecontacts 25 and 26 are sepa- 7 rated while the tool works substantiallyin the plane of the final surface of thework piece, whereby the con-'tinuation of the forwardifeedin g of the'grinding tool is automaticallystopped. After an adjustable period following said firstseparation ofthe contacts the machine may be returned to startingposition andarrested.

Hence, according to the construct-ions disclosed in the presentinvention, merely one disconnection is required during an entire workingoperation, viz. thedisconnection of the feeding means of the grindingtool. It will be seen, therefore, that according to the invention thenumber of the switching actions has been reduced to a minimum, makingpossible in this way a practically precise adjustment, Furthermore, thechecking block performs in the course of every working cycle merely onecontrol movement of minimum length (viz. 0.002 to 0.005 mm.) whichapplies also to the contacts and 26,

so that also in this way no'wear can occur and no disadvantagesaffecting the accuracy of the gauging job. In addition to this, thestationary arrangement of the feed control-device prevents the latterfrom interfering in any way with the normal handling of the-work-piecearranged on the circular supporting table; It is possibleythereon thesupporting table .tion; disconnectable feeding means arranged betweensaid support means and said grinding head means for gradually moving,when operatively connected,- said means relativcly to each other towardsa'final working position in which said grinding face coincides with aground surface of said work piece predetermined by said desired final 1dimension; and a pressure-responsive feed control device mountedstationarily with respect to said support means and at least partlyopposite said grinding face, and having a gauging member heldstationarily in a predetermined position of rest corresponding to saidfinal working I position of said grinding tool, for being subjected topressure by said grinding face when contactedby the latter during thefeeding operation of said feeding means, and adapted to be displacedfrom said position of rest and/thereby to disconnect said feeding meanswhen said grinding face arrives substantially in said final workingposition. a r

2. A flat grinding machine, comprising, in combination, a grinding headincluding a grinding tool having a gn'ndingfaceadapted to effect thesurface grinding of a work piece toa desired final dimension;disconnectable feeding means for feeding, when operatively'connectedwith siad girnding head, said grinding tool gradually into afinal working position in which said grinding face substantiallycoincides with a ground surface of said work piece predetermined by saiddesired-final dimension; and a feed control device stationarilymounted-at least partly opposite said grinding face and comprisinggauging means for determining the arrival of said grinding face in saidfinal working position, saidgauging means including a movable feelermember mounted to be displaced, from a stationary position of rest; by;-said grinding tool upon being g ta hr aid g nd fa q i r nsj e eedinnioveinent thefeof, anda disconnect memberoper'atively connected withsaid gauging member so as to be operated wheneversaid feelermetnbemisdisplaeedfrom its position of rest, and also operatively' connected-withsaid feeding means so as to disconnect the latter from operativenesswith respect to said grinding head upon such' displacement .of saidfeeler member .sothat hereby further feeding of said grinding head isprevented;

3: A .flat machine, comprising; in combination, a grindingheadincludinga, grinding tool having a grinding face-adapted to efiect the surfacegrinding .of a work piece. to. a desired final dimension; disconnectablefeedingmeans for feeding, when operatively connected with. said grindinghead, said grinding tool gradually into a fi nal working positioninwhich said grinding face substantially coincides with a ground surfaceof said work. piece predetermined by said desired final dimension; and afeed control device stationarily mounted at least .partly opposite saidgrinding face and comprising gauging means for determining the arrivalof said grind ingface in said final working position, and adjustable toany desired one of a plurality of operative'positions respectivelyassociated with a predetermined final working position, said gaugingmeans including a movable feeler member mountedto be displaced, from astationary position of rest determined by said 'desiredoperativeposition of said gauging means, by said grinding tool ,upon beingcontacted by said grinding face during the feeding movement thereof, anda "disconnect member operatively connected with said gauging member so.as to be operated whenever said feeler member is displaced from itsposition of rest, and also operatively connectedwith said feeding meansso as to disconnect the latter from operativeness with respect to saidgrinding head upon: such displacement of said feeler member so thathereby further feeding of said grinding head is prevented. V

A. A flat grindingmachine as set forth in claim 1,

vvhereinsaidigauging means are constructed to prevent,

upon said feeler means being contacted by said grinding face, furtherfeeding of said grinding head beyond a working position of said grindingface within .002 .to .005 mm. from said, work piece surfacepredetermined by the desired final dimension. ,7

5. A flat grinding machine comprising, in combination a grinding ,headincluding a grinding tool having a grinding face adapted to effect thesurface grinding of a work piece to a desired final dimension;disconnectable electrically controllable feeding means for feeding, whenoperatively connected with said grinding head, said grinding toolgradually into a final working position in which said grin-ding facesubstantially coincides with a ground surface of said work piecepredetermined by said desired final dimension; and a feed control devicestationarily mounted at least partly opposite said grinding face andcomprising gauging means for determining the arrival of said grindingface in said final working'position,'said gauging means including'amovable 'feelen-member mounted to be displaced, from a stationaryposition of rest, by said'grinding tool upon being contactedby saidgrinding face during-the feeding'rnovementth'ereof, and an electricaldisconnect member operatively co nnected with said gauging member so asto'be'operated Whenever said feeler member is displaced from itsposition of rest, and also electrically connected with saidfeedingmeansso as to disconnect electrically the latter from operativeness withrespect to said grinding head upon such displacement of said feelermember so that hereby further feeding of said grinding head isprevented.

6. A flat grinding machine, comprising, in combination, a grinding headincluding a grinding tool having a grinding face adapted to effect thesurface grinding of a Work piece to a desired final dimension;disconnectable feeding means for feeding, when operatively connectedwith said grinding head, said grinding tool gradually into a finalworking position in which said grinding face substantially coincideswith a ground surface of said work piece predetermined by said desiredfinal dimension; and a feed control device stationarily mounted at leastpartly opposite said grinding face and comprising gauging means fordetermining the arrival of said grinding face in said final workingposition, said gauging means including a movable feeler member having achecking portion of relatively abrasion-resistant material and beingmounted to be displaced, from a stationary position of rest, by saidgrinding tool upon being contacted at its checking portion by saidgrinding face during the feeding movement thereof, and a disconnectmember operatively connected with said gauging member so as to beoperated whenever said feeler member is displaced from its position ofrest, and also operatively connected with said feeding means so as todisconnect the latter from operativeness with respect to said grindinghead upon such displacement of said feeler member so that hereby furtherfeeding of said grinding head is prevented.

7. A flat grinding machine as set forth in claim 6, wherein said gaugingmeans include a substantially rodshaped feeler member having saidcontact portion arranged at one end thereof and abutting means at theopposite end thereof, guide means for shiftably supporting said feelermember, a disconnect member mounted in the path of said shiftablerod-shaped feeler member and equipped with a stationary contact and amovable contact piece respectively electrically connected with saidfeeding means, and bias means mounted to urge said movable contact pieceinto contact with said stationary contact, said abutting means beingarranged to abut against said movable contact piece for moving thelatter out of contact with said stationary contact against the action ofsaid bias means, so that whenever said feeler member is displaced saidfeeding means are electrically disconnected by the separation of saidstationary contact and movable contact piece.

8. A fiat grinding machine as set forth in claim 6, wherein said gaugingmeans includes a lever-type feeler member supported for being pivotallymoved when its contact portion is contacted by said grinding face, ashiftable rod-shaped transfer member having an abutting portion at oneend in operative contact with a portion of said lever-shaped feelermember, and having abutting means at the opposite end thereof, guidemeans for shiftably supporting said transfer member, a disconnect membermounted in the path of said sbiftable rod-shaped transfer member andequipped with a stationary contact and a movable contact piecerespectively electrically connected with said feeding means, and biasmeans mounted to urge said movable contact piece into contact with saidstationary contact, said abutting means being arranged to abut againstsaid movable contact piece for moving the latter out of contact withsaid stationary contact against the action of said bias means, so thatwhenever said feeler member is moved and said transfer member isdisplaced thereby, said feeding means are electrically disconnected bythe separation of said stationary contact and movable contact piece.

References Cited in the file of this patent UNITED STATES PATENTS1,228,798 Maag June 5, 1917 1,535,080 Spencer Apr. 21, 1925 1,549,600Mueller Aug. 11, 1925 FOREIGN PATENTS 89,285 Switzerland Sept. 16, 1921481,021 Great Britain Feb. 28, 1938

